Compositions containing organopolysiloxane fluids and aminofunctional silicone fluids as release agents are known in the art. For example U.S. Pat. Nos. 3,883,628 and 4,078,104 to Martin disclose release compositions for polyurethanes and bituminous materials containing an organopolysiloxane fluid and from 0.1 to 90 percent by weight based on the total weight of the composition of an aminofunctional silicone fluid.
Also, U.S. Pat. No. 38,938 to Koda et al describes methods for improving the heat stability of organopolysiloxane fluids by incorporating therein certain inorganic salts of metals such as iron, zirconium, cerium, manganese and nickel. Since these metals or metal salts are not compatible with the organopolysiloxane fluids, they were difficult to disperse uniformly throughout the composition. Other compositions which have been used to improve the heat stability of organopolysiloxane fluids are those obtained from the reaction of a cerium salt of an organic carboxylic acid and an alkali metal siloxanolate having at least three organosiloxane units per molecule.
Although the metal salts improve the heat stability of the silicone fluids, many of these metal salts are difficult to disperse therein in order to obtain a uniform dispersion. Another disadvantage of using metal salts to improve the heat stability of silicone fluids is that they are not all readily available. In contrast to the use of metal salts, as a heat stabilizer, the aminofunctional silicone fluids of this invention are readily available and they are compatible with the silicone fluids.
Therefore, it is an object of this invention to provide silicone fluids having improved heat stability. Another object of this invention is to provide silicone fluids containing a heat stabilizing agent that is easily dissolved therein. A further object of this invention is to provide a method for preparing silicone fluids having improved heat stability.